Electric sign devices



De l, 1970 NAQsuKE TsuBAKuMoTo ET AL 3,544,991

. v ELECTRIC 'SIGN DEVICES Filed June 7, 1965 2 sheets-sheet x INVENTORS Haosuke Tsubakmoto Yasuaka Kawase.

Hiroyuki Masushl'a ATTORNEYS United States Patent O 3,544,991 ELECTRIC SIGN DEVICES Naosuke Tsubakimoto, Ibaraki-shi, Yasntaka Kawase, Kyoto-shi, and Hiroyuki Matsushita, Takatsuki-shi, Japan, assignors to Matsushita Electronics Corporation, Kadoma-shi, Japan, a corporation of Japan Filed June 7, 1965, Ser. No. 461,705 Claims priority, application Japan, June 17, 1964, 39/34,764 Int. Cl. G08b 5/36 U.S. Cl. 340-339 4 Claims ABSTRACT OF THE DISCLOSURE An electric sign device for displaying an image on a screen formed by a number of electric luminous elements mounted in stages. An original picture on a tape is read by photoelectric conversion type readers. The output of the readers is fed to shift registers to selectively control the energization of the luminous elements to form bright and dark areas corresponding to the original picture. The shift pulses are obtained by using a number of dots provided on the tape in its lengthwise direction.

This invention relates to an improvement in electric sign devices of the type provided with a sign board having a substantially rectangular screen formed of a multiplicity of electric luminous elements and a signal generator for movingly reproducing on the screen an image having lighted areas and darkened areas corresponding to an original picture provided on a tape.

The first object of the present invention is to provide an electric sign device of the type described in which the structure of the generator for producing electric signals corresponding to an original picture on a moving tape is extremely simplified.

The second object of the present invention is to provide an electric sign device of the type described in which the number of wires connecting the generator with the sign board is greatly reduced. That is, the invention intends to minimize the amount of wires required when the sign board is disposed at a place remote from the signal generator.

The third object of the present invention is to provide an electric sign device in which the use of a bulky mercury switch mechanism in the generator as has been the case with prior devices is completely eliminated and in which even if such mercury switch mechanism should be used the generation of detrimental mercury vapor can be minimized.

The fourth object of the present invention is to provide an electric sign device of the type described in which arrangement is made so as to facilitate positive-negative inversion of an image produced on the sign board or to facilitate impartatio-n of color thereto.

According to the present invention, there is provided an electric sign device comprising a sign board having a substantially rectangular screen formed of a multiplicity of electric luminous elements arranged in multiple stages, an electric signal generator for generating electric signals for movingly reproducing on said screen an image corresponding to an original picture provided on a tape, means for supplying to said generator input signals representing a linear state of a certain position on said tape, means for applying output signals from siad generator to a predetermined number of the elements linearly disposed in one stage of the multiplicity of electric luminous elements arranged in multiple stages and electronic circuits for controlling electric signals to be supplied to the electric luminous elements in the stages other than ICC said stage, each of said electronic circuits being disposed between one electric luminous element in each stage and one electric luminous element in the preceding stage.

The above and other objects, advantages and features of the present invention will become apparent from the following description with reference to the accompanying drawings, in which:

FIG. l is a perspective view of a signal generator employed in the electric sign device embodying the present invention;

FIG. 2 is a schematic diagram of parts of a circuit network employed in one embodiment of the electric sign device of the present invention;

FIG. 3 is a schematic diagram of parts of a circuit network employed in another embodiment according to the present invention;

FIG. 4 is a schematic illustration of waveforms at various points in the circuit network shown in FIG. 3;

FIG. 5 is a plan view of part of a tape which can conveniently -be used with the electric sign device of the present invention; and

FIG. `6 is a schematic diagram of a circuit network of the present invention for imparting color to images appearing on the sign board.

An important feature of the device according to the present invention resides in that electric signals corresponding to an original picture are not derived from a planar state at each instantaneous position of a tape moving over a signal generator but from a linear state obtained by finely dividing such planar state. In the present invention, these electric signals are utilized to directly effect on-off control of only a predetermined portion of entire electric luminous elements, and on-off control of each element of the remaining greater portion of the electric luminous elements is effected in a manner that an electric signal controlled by an electronic circuit provided between each electric luminous element and a preceding electric luminous element positioned at the prestage is utilized to make on-olf control of each element.

Some of preferred embodiments of this invention will now be described in detail hereunder.

In FIG. l showing in perspective fashion an example of the signal generator employed in the invention, r1, r2, r3 rn designate photoconductive cells formed of CdS, CdSe or like material. On the upper face of a base B of electrically insulating material these photoconductive cells are disposed in a straight line, with an even space between adjacent cells. A transparent tape T moves in a direction as for example shown by an arrow through a gap between the base B and a light source L disposed thereabove by being aided by a suitable feed mechanism. An original picture C is drawn on the tape surface with an opaque paint material.

The photoconductive cells r1, r2, r3, rn maintain small resistance by the light emitted from the light source L unless the original picture C appears in the gap between the photoconductive cells r1, r2, r3, rn and the light source L. When however a linear strip portion of the original picture C intrudes into the gap with the advancing movement of the moving tape T, the path of the light towards the photo-conductive cells is interrupted and the resistance of the second photoconductive cell r2 makes an abrupt increase in the case illustrated in FIG. l.

As will be apparent from FIG. 2 showing parts of a circuit network employed in one embodiment of the device of the present invention, the increase in the resistance of the photoconductive cell r2 results in reduction of voltage across a resistor R1 since the photoconductive cell r2 is connected to a source of direct current supply '+B through the resistor R1. Therefore this causes generation of one pulse signal in the output of a waveform shaping circuit F. This pulse signal is applied to one of units T21,

such as a transistor, forming together with other unit T21 a bi-stable multi-vibrator which acts as a pre-circuit for an electric luminous element 121 positioned in line 2, stage 1 of the sign board. Thus, the unit T21 is driven to its cut off state while the other unit T21 which may also be a transistor is driven to its-on state. As a result, current conducts through a relay coil Re21 to change over switches S21 and S21 to respective operative positions. Consequently, the electric luminous element [21 positioned in line 2, stage 1 of the sign board is lit.

In this manner, the optical state (that is transparent or not) of the portion of picture superimposed at a certain instant on the photoconductive cells r1, r2, r3, rn causes electrical change in photoconductive cells corresponding to above-mentioned portion of picture, and electrical signals are obtained therefrom.

These signals effect direct on-off control of the elements disposed in the first stage of the multiplicity of electric luminous elements arranged in multiple stages to form the screen of the sign board.

In the embodiment shown in FIG. l, a moving tape T of light transparent nature and an original picture C of opaque nature have been employed to obtain electric signals from the light transmitted through the tape T. However, a moving tape T of high reflexibility and an original picture C f low reexibility may be used so that electric signals corresponding to the original picture may be derived from reflected light.

According to the invention, an arrangement is provided so that, in the course of the above manner of control of luminous elements disposed in the iirst stage of the multiplicity of electric luminous elements, positive pulses are periodically supplied at predetermined time intervals to a terminal p which is connected with the output of a suitable pulse generator. One positive pulse supplied to the terminal p is transmitted through a diode d21 and the switch S21 to one of units T22, such as a transistor, forming together with other unit T22', a bi-stable multivibrator which acts as a pre-circuit for an electric luminous element Z22 disposed in line 2, stage 2 of the sign board. Therefore the unit T22 is driven to its cut off state while the other unit T22 which may also be a transistor is driven to its on state, and iinally the electric luminous element Z22 is energized. When a succeeding positive pulse is supplied to the terminal p, an electric luminous element 123 disposed in line 2, stage 3 is energized this time. Thus, the electric luminous elements disposed in line 2 of the sign board are successively subjected to sequence control in the direction of line 2 and the time interval of sequence control is in synchronism with the time intervals of generation of the pulses applied to the terminal p.

It will be understood that, while this on-of control in the direction of the line proceeds, new electric signals corresponding to the advancing original picture are successively generated by the photoconductive cell r2 and these signals directly (for the first stage) and indirectly (for the stages after and including the second stage) efect the on-otf control of electric luminous elements `121, 122, [23, one after another. Further it is possible to effect positive-negative inversion of the bright-dark contrast image by connecting the unit T21 with the output of the waveform shaping circuit F instead of the previous connection between the unit T21 and the output of the circuit F. It is to be understood that any one of the photoconductive cells r1, r3, rn is provided with a circuit as shown in FIG. 2 since the circuit network shown in FIG. 2 does not represent the entirety of the device of the present invention and merely represents that portion which is associated with the specific photoconductive cell r2.

The circuit network employed in the device according to the present invention may be modified, for example, as shown in FIG. 3. A modified example of the circuit network shown in FIG. 3 will next be described with further reference to FIGS. l, 4 and 5.

In the circuit network of FIG. 3, the photoconductive cell r2 is connected through a resistor R101 to a source of direct current supply and a differentiating circuit comprising a condenser C101 and a resistor R102 is added for cooperation with the photoconductive cell r2. Suppose now a moment at which the tape T is advanced further with the result that an original picture having existed in the gap between the photoconductive cell r2 and the light source L is shifted so that a transparent portion of the tape now exists in the gap and a positive pulse as shown by p1 in p of FIG. 4 is applied to a terminal p. At this moment, the resistance of the photoconductive cell r2 makes an abrupt decrease and a positive signal as shown by a1 in a of FIG. 4 is generated at point a in FIG. 3. Since this signal drives a transistor Tr1 to its cut off state and a transistor Tr2 to its on state, condensers C102 and C103 start discharging and charging, respectively, and potential at point b in FIG. 3 decreases gradually as shown by b1 in b of FIG. 4 until nally it equals the potenial -B. Under this situation, current flowing through a relay coil Re121 is cut to urge a switch S121 to its open position so that an electric luminous element l121 disposed in line 2, stage 1 of the sign board is deenergized. On the other hand, the pulse p1 applied to the terminal p is supplied through a reistor R103 and a diode d101 to the base electrode of a transistor Tr.1 which, in conjunction with another transistor Tr3, forms a bi-stable multivibrator which acts as a pre-circuit for an electric luminous element Z122 disposed in line 2, stage 2 of the sign board. At the moment when the pulse p1 is applied to the terminal p the potential at point b is immediately before its gradual decrease and is still high. Therefore the pulse p1 can not ow into the system through a diode c1102. Although the pulse p1 applied to the terminal p is also transmitted to point c through a resistor R104 and a diode d103, the transistor Tr1 is not affected at all because the transistor T r1 is being driven to its cut off state.

The combination of these two actions drives the transistors Tra and Tr.1 to their on state and cut off state, respectively, and as a result, the pulse p1 applied to the terminal p causes the electric luminous element Z121 to be deenergized, while the electric luminous element 1122 disposed in line 2, stage 2 of the sign board is urged to its energized state as if it follows the past behaviour of the element Z121- Suppose then a moment at which a second pulse as shown by p2 in p of FIG. 4 is applied to the terminal p in FIG. 3. Also assume that a transparent portion of the tape T again exists in the gap between the photoconductive cell r2 and the light source L at this moment. In this case no electric signal appears at point a and therefore the element Z121 continues its deenergized state. Since, on the other hand, the potential at point b is now suciently low, the pulse p2 applied to the terminal p is conducted into the system through the resistor R103 and the diode d102 but not through the diode c1101. Further, since the potential at point C is now high, the pulse p2 is not conducted through the diode i103 but is conducted to the base electrode of the transistor Tra through the resistor R104 and a diode d104. Thus, the transistors Tr3 and Tr., are driven to their cut off state and on state, respectively, and linally the element Z122 is urged to its deenergized state as if it follows the way the element Z121 behaved in past.

When, however, an original picture C of opaque nature is inserted in the above gap at the moment when the pulse as shown by p2 in p of FIG. 4 is applied to the terminal p, the resistance of the photoconductive cell r2 increases with the result that a negative signal as shown by a2 in FIG. 4 is generated at point a in FIG. 3. This causes inversion of the states of the transistors Tr1 and T r2, that is, the transistors Tr1 and Tr2 are now driven to their on state and cut off state, respectively. As a result, the potential at point b makes a gradual increase as shown by b2 in b of FIG. 4 and current conducting through the relay coil Re121 urges the switch S121 to its closed position so that the element Z121 is finally energized. The transistor Tr2 in its cut off state assists discharging of the condenser C103 and the potential at point c makes a gradual decrease as shown 'by c2 in c of FIG. 4. On the other hand, the pulse p2 applied to the terminal p is conducted to point b which is at a potential immediately before making a gradual increase and is not conducted to the diode dm. Since however the potential at point c is still high as it is immediately before making its gradual decrease, the pulse p2 is applied through the resistor R104 and the diode i101 to the base electrode of the transistor Tra to drive the transistor Tr3 to its cut ofr state to thereby urge the switch S122 to its open position. Consequently the element Z122 is urged to its deenergized state as if it follows the way the element 1121 behaved in the past.

An important matter in connection with the present circuit arrangement is that the original picture C depicted on the moving tape T must be strictly synchronized with the time intervals of generation of pulses applied to the terminal p because a bright-dark contrast image appearing on the sign board is generated in accordance with the time intervals of generation of pulses applied to the terminal p from a certain external means not shown in the figure and is successively fed in the direction of the line. A concrete example will be described as follows in order to explain the above matter in more detail. Assume now that an original picture, for example, a sign 1l is passed through the gap between the light source L and the photoconductive cells r1, r2, r2, rm in FIG. l. In this case, satisfactory sign display operation can be effected When a rst pulse is applied to the terminal p as soon as the photoconductive cells r1, r2, r3, rm catch the righthand half or l of the original picture and a second pulse is applied to the terminal p as soon as the photoconductive cells catch the left-hand half or l of the original picture. However, a bright-dark contrast image corresponding to the original picture can not be displayed on the sign board if a first pulse is applied to the terminal p immediately before the original picture l1 reaches the photoconductive cells, a second pulse is applied at the intermediate position of the picture on the cells, and a third pulse is applied immediately after the picture has passed over the cells.

In order to overcome such diiriculty, the present invention proposes a new type of moving tape T' which is provided with a multiplicity of black dots E printed on its lower edge in equally spaced relation as shown in a plan view of FIG. 5. It will be understood that the above diiculty can be overcome by depicting an original picture C in a manner to correspond with the group of black dots E and by using the group of black dots E to generate pulses for application to the terminal p.

-From the above description exemplifying the preferred embodiments, it will be understood that, in the device according to the present invention, electric signals derived from an original picture are solely supplied to electric luminous elements disposed in the rst stage of a multiplicity of electric luminous elements arranged in multiple` board, and the photoconductive cells employed herein may be replaced by other types of elements such as photoelectric converting elements.

An example of an additional circuit for imparting color to a bright-dark contrast image to be displayed on the sign board will next be described with reference to FIG. 6. In FIG. 6, each of a multiplicity of electric luminous elements [221, 1222, 1223., forming the screen of the sign board comprises a set of lamps emitting colors different from one another, for example, a lamp IR for emitting red light, a lamp IB for emitting blue light and a lamp IG for emitting green light. Assume now that both of photoconductive cells rX and ry are held in their non-conducting state with or without relation to the advancing movement of a tape. Then relay switches Sx and Sy are held at relative positions as shown and as relay switches S221, S222, S223,

. are successively closed a bright-dark contrast image displayed on the sign board will be colored in red. In case the photoconductive cell rX is held in its nonconducting state and the photoconductive cell ry is held in its conducting state with the result that the switch Sy is urged to the other operative position, the bright-dark contrast image will now be colored in blue. The image will be colored in green when both of the cells rX and ry are held at their conducting state.

What is claimed is:

1. An electric sign device comprising a sign board having a screen formed by a plurality of electric luminous elements arranged in multiple stages, tape means having an original picture provided thereon, a plurality of sequentially arranged, optically detectable dots provided along one edge of said tape, means to drive said tape, photo-electric conversion type reader means mounted to read said tape and form output signals representing an optical scan of a linear strip portion of the picture on the tape and shift pulses corresponding to scanning of said dots, a plurality of shift registers operatively connected to receive said output signals and shift pulses and to correspondingly control energization of said luminous elements, each said shift register being disposed between one electric luminous element in one stage and an electric luminous element in the preceding stage, whereby bright and dark images corresponding to the original picture are formed on the screen.

2. An electric sign device according to claim 1, wherein said shift registers comprise bi-stable multivibrators in cascade connection.

3. An electric sign device according to claim 1, wherein said reader means comprise a plurality of photo-electric converting elements arranged in a row in suitably spaced relationship and at least one light source, said tape being passed between said converting elements and said light source.

4. An electric sign device according to claim 1, wherein said electric luminous elements each comprise a plurality of lamps of different colors.

References Cited UNITED STATES PATENTS 2,649,502 8/1953 Odell 340--339 3,225,342 12/1965 Clark 340--324 2,123,459 7/ 1938 Andersen 340--339 2,454,238 11/1948 Waller et al 340-339 3,273,140 9/1966 Foster et al 340-339 3,283,318 11/1966 Bramer '340-339 3,222,666 12/ y1965 Holden 340-324 THOMAS B. HABECKER, Primary Examiner M. M. CURTIS, Assistant Examiner Us. c1. Xn. 340-334, 336

fgyg@ UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,544,991 Dated DeCember l, 1970 Inventods) Naosuke TSUBAKIMOTO et al It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Please add the following Japanese Patent Application N 46517 filed August l0, 1964 as the other application upon which Convention Priority is based as is set forth in the Declaration filed with the Application.

Signed and sealed this 7th day of September 1971.

(SEAL) Attest:

EDWARD M.FLETGHER,JR. ROBERT GOTTSCHALK Attesting Officer Acting Commissioner of Pate 

